Nicola Sturgeon has hit back at accusations that SNP supporters are "brainwashed" as parties kick-started campaigning for this year's Scottish Parliament election.

Scotland's First Minister said the suggestion was "profoundly insulting" in an opinion piece setting out her priorities in the run up to the vote on May 5.

The SNP leader also pledged to "lead a renewed debate" about independence, despite calls from Labour to move on from constitutional wrangling in the wake of 2014's referendum, the Press Association reports.

Ms Sturgeon will lead a New Year debate at Holyrood on Tuesday pledging to "earn the right" to an unprecedented third term in government.

Nicola Sturgeon having a selfie with supporters

She has promised a raft of new policies on health, education, social security and the economy in the run up to polling day.

Opinion polls indicate the SNP is currently on course to increase its majority in the Scottish Parliament.

Ms Sturgeon said: "My response to polls is always to remind my party that we must never take a single vote for granted – a point I will make again today.

"But increasingly in Scotland we see, from opposition parties and certain commentators, another response – one that cites the scale of SNP support as evidence that the country has abandoned its critical faculties in favour of blind loyalty.

"I can understand why the opposition parties find that notion comforting – it's easier than having to face up to their own shortcomings. But as an analysis, it is profoundly insulting to the Scottish people.

"Those who support the SNP have not been brainwashed, they are not blind to our imperfections – instead, they are weighing them against our strengths and achievements, and against the other parties, and deciding that the SNP is the party they most closely identify with, the people they trust most to stand up for Scotland."

She added: "I've said already that a second referendum should only happen if there is a material change of circumstances or when we have evidence of a significant change of opinion from that expressed in September 2014.

"It is our job now to lead a renewed debate about how the enduring principle of the independence case – that decisions about Scotland are best taken by people who live here – is relevant to, indeed demanded by, the circumstances of the world we live in today.

"It is by making the case, positively and powerfully – and in a realistic and relevant way – that we will persuade those we didn't persuade in 2014 and, over the next few years, turn 45% into a majority."

Scottish Labour leader Kezia Dugdale is due to unveil her party's first election pledge on housing in a speech to activists in Edinburgh on Tuesday.